US Army Medical Course MD0173-100 - Pesticides in the Military

8/14/2019 US Army Medical Course MD0173-100 - Pesticides in the Military

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U.S. ARMY MEDICAL DEPARTMENT CENTER AND SCHOOLFORT SAM HOUSTON, TEXAS 78234-6100

PESTICIDES IN THE MILITARY

SUBCOURSE MD0173 EDITION 100


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DEVELOPMENT

This subcourse is approved for resident and correspondence course instruction. It reflects thecurrent thought of the Academy of Health Sciences and conforms to printed Department of theArmy doctrine as closely as currently possible. Development and progress render such doctrinecontinuously subject to change.

When used in this publication, words such as "he," "him," "his," and "men" 'are intended toinclude both the masculine and feminine genders, unless specifically stated otherwise or whenobvious in context.

The instructional systems specialist responsible for development of this edition was William H.Shade, DSN 471-8906 or commercial (210)221-8906; Academy of Health Sciences, MultimediaDevelopment Branch, ATTN: MCCS-HLD, 2250 Stanley Road (Room 326), Fort Sam Houston,Texas 78234-6130.

The subject matter experts responsible for writing and content accuracy of this edition were fromPreventive Medicine Division, DSN 471-8909 or commercial (210)221-8909; Commander, U.S.

Army Medical Department Center and School, ATTN: MCCS-MP, Fort Sam Houston, Texas78234-6100.

ADMINISTRATION

Students who desire credit hours for this correspondence subcourse must meet eligibilityrequirements and must enroll through the Nonresident Instruction Branch of the U.S. ArmyMedical Department Center and School (AMEDDC&S).

Application for enrollment should be made at the Internet website: http://www.atrrs.army.mil.You can access the course catalog in the upper right corner. Enter School Code 555 formedical correspondence courses. Copy down the course number and title. To apply for

enrollment, return to the main ATRRS screen and scroll down the right side for ATRRSChannels. Click on SELF DEVELOPMENT to open the application and then follow the onscreen instructions.

In general, eligible personnel include enlisted personnel of all components of the U.S. Army whohold an AMEDD MOS or MOS 18D. Officer personnel, members of other branches of theArmed Forces, and civilian employees will be considered eligible based upon their AOC, NEC,AFSC or Job Series which will verify job relevance. Applicants who wish to be considered for awaiver should submit justification to the Nonresident Instruction Branch at e-mail address:[email protected].

For comments or questions regarding enrollment, student records, or shipments, contact the

Nonresident Instruction Branch at DSN 471-5877, commercial (210) 221-5877, toll-free 1-800-344-2380; fax: 210-221-4012 or DSN 471-4012, e-mail [email protected], or write to:

NONRESIDENT INSTRUCTION BRANCHAMEDDC&SATTN: MCCS-HSN2105 11TH STREET SUITE 4191FORT SAM HOUSTON TX 78234-5064


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TABLE OF CONTENTS

Lesson Paragraphs Page

INTRODUCTION iii

1 INTRODUCTION TO PESTICIDESSection I. General 1-1--1-4 1-2Section II. Insecticides 1-5--1-7 1-4Section III. Rodenticides 1-8--1-10 1-10Section IV. Fumigants and Fungicides 1-11--1-12 1-12Section V. Herbicides 1-13--1-15 1-13Exercises 1-16

2 PESTICIDE MIXING AND CALCULATIONS

Section I. Pesticide Formulations 2-1--2-8 2-2Section II. Pesticide Mixing Calculations 2-9--2-11 2-7Section III. Pesticide Application Calculations2-12--2-14 2-12Exercises 2-17

3 PESTICIDE SAFETY

Section I. Personnel and Training 3-1--3-2 3-2Section..II. Safe Handling and Storage3-3--3-9 3-3Section III. Pesticides and the Environment3-10--3-17 3-12Exercises 3-19

4 HAZARD COMMUNICATION PROGRAM

Section I. The Federal Hazard CommunicationStandard 4-1--4-2 4-2

Section II. Chemical Forms and ExposureHazards 4-3--4-6 4-4

Section III. Types of Physical and Health Hazards 4-7--4-11 4-6Section IV. Controlling Chemical Hazards 4-12--4-15 4-9Section V. Material Safety Data Sheets and

Physical Hazard Information 4-16-4-21 4-11Section VI. Material Safety Data Sheets and

Physical Hazard Information 4-22--4-23 4-17Section VIII. Using Labels and the Hazardous

Chemical Inventory 4-24--4-26 4-17Exercises 4-22


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LIST OF ILLUSTRATIONS

Figure Page

2-1 Formulation of dusts and suspensions 2-5

2-2 Formulation of solutions and emulsions.. 2-62-3 Volumetric calculations.. 2-82-4 Weight/volume calculations 2-112-5 Standard pesticide label.. 2-154-1 Material Safety Data Sheet.. 4-144-2 Hazard Warning Label.. 4-194-3 Hazard Chemical Inventory.. 4-21

LIST OF TABLES

Table Page

1-1 Toxicities of common insecticides 1-91-2 Standard military herbicides and their characteristics 1-153-1 Pesticides and antidotes 3-114-1 Toxicity and its effects 4-5


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CORRESPONDENCE COURSE OFTHE U.S. ARMY MEDICAL DEPARTMENT CENTER AND SCHOOL

SUBCOURSE MD0173

PESTICIDES IN THE MILITARY

INTRODUCTION

Pesticides are nothing new. Various pesticides, such as lead arsenate, nicotinecompounds, and others, have been in use for years. It is even thought that Marco Polobrought pyrethrum, the active ingredient in most aerosol insecticides, back to Europeafter his trip to the Orient. The widespread use of synthetic pesticides, however, did notoccur until after World War II. DDT, whose insecticidal properties were first recognized

in 1939, was used by U.S. military forces during the war with great success. For thefirst time in our military history, the individual carried an effective delousing agent withhim as a normal part of his paraphernalia. DDT also played an important role in thepostwar civil affairs program, as our occupation forces assisted in the rehabilitation ofdevastated areas.

Today the Army possesses a formidable array of pesticides, most of which aresynthetic (man-made). The pesticides available for use by the environmental healthtechnician include compounds having a wide range of toxicity, some being lethal to manin milligram dosages while others may be tolerated in moderate amounts without fatalresults. The wide variety of toxic agents available offers considerable selectivity inchoosing a pesticide which will achieve the desired result against a target pest whilehaving only limited effects against beneficial insects or other animal life.

In order to intelligently and effectively employ the pesticides available,environmental health technicians and engineer personnel must understand theprinciples of toxicology and know the toxicity of the various pesticides. They must alsoknow the classes of pesticides and the proper use of each. In addition, they shouldknow how to calculate and mix pesticide formulations and be familiar with the variousmeans of dispersal. Finally, they should be aware of the necessary safety precautionsin the use of military pesticides. It is the objective of this subcourse to provide thenecessary competence in these areas.

Subcourse Components:

This subcourse consists of four lessons and an examination. The lessons are:

Lesson 1, Introduction to Pesticides.

Lesson 2, Pesticide Mixing and Calculations.


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Lesson 3, Pesticide Safety.

Lesson 4, Hazard Communication Program.

Credit Awarded:

Upon successful completion of this subcourse, you will be awarded 8 credithours.

Materials Furnished:

Materials provided include this booklet, an examination answer sheet, and anenvelope. Answer sheets are not provided for individual lessons in this subcoursebecause you are to grade your own lessons. Exercises and solutions for all lessons arecontained in this booklet. You must furnish a #2 pencil.

Procedures for Subcourse Completion:

You are encouraged to complete the subcourse lesson by lesson. When youhave completed all of the lessons to your satisfaction, fill out the examination answersheet and mail it to the AMEDDC&S, along with the Student Comment Sheet, in theenvelope provided. Be sure that your social security number is on all correspondencesent to the AMEDDC&S. You will be notified by return mail of the examination results.Your grade on the examination will be your rating for the subcourse.

Study Suggestions:

Here are some suggestions that may be helpful to you in completing thissubcourse:

--Read and study each lesson carefully.

--Complete the subcourse lesson by lesson. After completing each lesson, workthe exercises at the end of the lesson, marking your answers in this booklet.

--After completing each set of lesson exercises, compare your answers withthose on the solution sheet, which follows the exercises. If you have answeredan exercise incorrectly, check the reference cited after the answer on thesolution sheet to determine why your response was not the correct one.

--As you successfully complete each lesson, go on to the next. When you havecompleted all of the lessons, complete the examination. Mark your answers inthis booklet; then transfer your responses to the examination answer sheetusing a #2 pencil and mail it to the AMEDDC&S for grading.


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Student Comment Sheet:

Be sure to provide us with your suggestions and criticisms by filling out theStudent Comment Sheet (found at the back of this booklet) and returning it to us withyour examination answer sheet. Please review this comment sheet before studying this

subcourse. In this way, you will help us to improve the quality of this subcourse.


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LESSON ASSIGNMENT

LESSON 1 Introduction to Pesticides.

LESSON ASSIGNMENT Paragraphs 1-1--1-15.

LESSON OBJECTIVES After completing this lesson, you should be able to:

1-1. Identify the categories of pesticides used by theArmy.

1-2. Identify the means by which insecticides enterthe bodies and act upon arthropods.

1-3. Classify pesticides according to their chemical

composition and approved usage.

1-4. Apply the terms LD50 and LC50 in determiningrelative pesticide toxicity.

SUGGESTION After completing the assignment, complete theexercises of this lesson. These exercises will helpyou to achieve the lesson objectives.


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Section I. GENERAL

1-1. CATEGORIES OF PESTICIDES

Pesticides are chemicals that are used to kill unwanted insects, animals, orplants. Categories of pesticides used in the Army include the following.

a. Insecticides. Insecticides are chemicals used to kill insects or other closelyrelated arthropods, such as spiders, ticks, mites, and scorpions.

b. Rodenticides. Rodenticides are used primarily against rats and mice, buttheir intended targets may also include such animals as gophers, rabbits, squirrels, andother small rodents.

c. Fungicides. Fungicides are chemicals used to kill or prevent the growth of

fungi.

d. Herbicides. Herbicides are chemicals used in controlling weeds orunwanted vegetation.

1-2. STANDARD MILITARY PESTICIDES

a. The pesticides standardized for military issue have been carefully selectedto provide a minimum number of items with maximum military application and safety.These items, if used as recommended, should provide satisfactory control of pests ofmilitary importance. Standard pesticides are reviewed, updated, and approvedperiodically by the Armed Forces Pest Management Board.

b. Pesticides are considered controlled items. Approval from higherheadquarters is required for their procurement. Because of their toxicity and/orconcentration, they may be applied only by, or under the direct supervision of, trainedand certified personnel. Such personnel are normally assigned to an installationdirectorate of facilities engineering, a regional division of the U.S. Center for HealthPromotion and Preventive Medicine (USACHPPM), or a preventive medicinedetachment.

1-3. NONSTANDARD PESTICIDES

Situations may arise in which the staff pest management professional determinesthat a nonstandard pesticide is required for a special program. When a nonstandardtime is required, the using unit must submit a request for local purchase to its approvingheadquarters. The request will provide full justification of the need for the nonstandarditem. Pesticides discussed in this text that are nonstandard will be so identified.


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1-4. TOXICITY

All pesticides must be considered potentially toxic (poisonous) to man andanimals. However, the degree of toxicity is only one of several factors in the use ofpesticides that determine the hazard to man. The primary hazard lies in failure to follow

the precautions and directions for use indicated on the pesticide label. Safe handling ofpesticides is discussed in Lesson 3; however, measurement of toxicity will be explainedat this point since these terms will be used throughout the discussion of pesticides.

a. LD50 Value.

(1) The LD50 (lethal dosage) value of a pesticide -- or any other toxicsubstance -- is a statistical estimate of the dosage necessary to kill 50 percent of apopulation of test animals (usually white rats) with a single exposure under standardizedconditions in the laboratory. It is expressed in milligrams of poison per kilogram of bodyweight (mg/kg) for rodents or micrograms per gram (mg/gm) for insects. The LD50

values do not take into account the physical condition of laboratory animals, nor do theyprovide data on the cumulative effects of repeated dosages; however, they do enableus to compare the relative acute toxicities of various pesticides. The higher the LD50value, the lower the toxicity since more poison is required to affect a death. Thus, apesticide with an LD50 value of 500 mg/kg is more toxic than one with an LD50 value of1,000 mg/kg.

(2) Toxicity is expressed as an oral or dermal LD50 value, which variesdepending on whether the poison is taken orally (by mouth) or dermally (absorbedthrough the skin). Most pesticides have a considerably higher dermal than oral LD50.Unless otherwise specified, LD50 values quoted in this subcourse are oral values. Inconsidering LD

50values, it must be remembered that these values have been

determined from experimental data on laboratory animals; therefore, they cannot beconsidered exact values nor can they be directly transferred as effects on man.

(3) Various toxicologists have devised tables of relative toxicities basedupon the LD50 derived from test animals and extrapolated (estimated correspondingeffect) to humans. These tables usually begin with an LD50 of more than 5000 mg/kg(over a quart for a 150-pound man) as relatively harmless or practically nontoxic. Mosttables rate a chemical having an LD50 of less than 50 mg/kg as highly toxic, 50 to 500mg/kg as moderately toxic, 500 to 5000 mg/kg as slightly toxic, and greater than 5000mg/kg as practically nontoxic.

b. LC50 Value. The LC50 (lethal concentration) value of a poison is theconcentration in parts per million (ppm) of the poison applied to the environmentrequired to kill 50 percent of a test population (fish, mosquito larvae, etc.) from a singleexposure under standardized conditions. Like the LD50 value, a high LC50 valueindicates low toxicity and vice versa. It should be emphasized here that LD50 and LC50values cannot be compared to one another since they are derived from two different


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sets of test conditions. Like LD50 values, LC50 values are approximate values obtainedon the basis of laboratory tests.

Section II. INSECTICIDES

1-5. CLASSIFICATION ACCORDING TO MODE OF ENTRY

There are three types of insecticides when classified according to the mode ofentry into the insect's (arthropod's) body.

a. Oral. Oral poisons must be swallowed in order to kill the insect. They areused against insects with chewing, sponging, or lapping mouthparts. These insecticidesare usually applied in the form of dusts or sprays to vegetation or other natural foodseaten by the target insect. The insect consumes the insecticide when it eats the foliage

or when it cleans appendages to which the insecticide has adhered through contact withtreated surfaces. Stomach poisons may also be mixed with baits that are moreattractive to the insects than natural foods. A satisfactory stomach poison must bequick acting, inexpensive, and available in large quantities. It must be palatable to thetarget insects, or they will avoid it. The insecticides used as stomach poisons arechiefly the inorganic chemicals (para 1-6a) and some of the chlorinated hydrocarbons(para 1-6c(1)).

b. Dermal. Dermal poisons kill insects by contacting and entering the bodyeither directly through the body wall and into the blood, through the mouthparts and intothe digestive system, or through the respiratory system. These insecticides are usedprimarily against insects with sucking mouthparts, which would not eat normally appliedstomach poisons. However, they are also effective as stomach poisons if eaten byinsects with chewing mouthparts. Contact poisons may be applied directly to insects'bodies as sprays or dusts, or they may be applied for residual action on surfaces withwhich the target insects will come in contact. Contact insecticides in common useinclude the natural organic (para 1-6b) as well as the synthetic organic (para 1-6c)compounds.

c. Respiratory. Respiratory chemicals are volatile chemicals that kill byentering a pest through the respiratory system. They are used in gaseous form or assolids or liquids which rapidly vaporize forming poisonous gases. They are particularlyappropriate for killing insects in stored products where the gas will penetrate cracks,crevices, and tightly packed material. They are extremely toxic to all animal life;therefore, they are also effective as rodenticides. Their extreme toxicity makesfumigants particularly hazardous to use; accordingly, their use is restricted to trainedand certified personnel. They are discussed in Section IV.


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1-6. CLASSIFICATION ACCORDING TO CHEMICAL COMPOSITION

Because some insecticides may fall into several categories when classifiedaccording to mode of entry (many, for example, are both stomach poisons and contactpoisons), it is more convenient to classify them according to their chemical composition.

While differences exist between insecticides within a category, each category hascharacteristics that are applicable, in general terms, to the insecticides in that group.

a. Inorganic Insecticides. Inorganics do not contain carbon, and they oftencontain metals or other chemical elements. Most are stomach poisons. Examplesinclude boric acid, borate, silica aerogel, and sulfur. Others no longer used includecopper acetoarcinate, lead arsenate, mercury, and zinc phosphide.

b. Natural Organic Insecticides. Natural organic insecticides are derivativesor refined forms of organic compounds occurring naturally. They may be botanicals(from plants) or products from petroleum and coal tar.

(1) Botanicals.

(a) Pyrethrum. Pyrethrum is the term applied to the insecticidalcompounds of the flower heads of Chrysanthemum (Pyrethrum) cinerariaefolium. Fourseparate compounds are included, of which Pyrethrum I is the most active. Commercialpyrethrum extract is a yellow, oily liquid insoluble in water but soluble in a number ofcommon organic solvents. Pyrethrum is a powerful contact insecticide causing a rapidparalysis or "knockdown" of the treated insects. Its efficiency is increased by the use ofa synergist such as piperonyl butoxide. Pyrethrum is effective as a direct contact sprayagainst adult flies, mosquitoes, and other flying household insect. It lacks persistence,having virtually no residual action. Many insects recover after an initial attack.Pyrethrum is one of the least toxic insecticides to mammals, having an LD50 value onthe order of 1,500 mg/kg. It breaks down rapidly, posing no environmental hazard.

NOTE: A synergist is a compound which, when added to an insecticide, willincrease the insecticidal toxicity so that the amount of insecticide neededcan be decreased. Many synergists, such as piperonyl butoxide, MGK 264,sulfoxide, and sesamin are used in fly and mosquito control, particularly inaerosol bombs and space sprays.

(b) Nicotine. Nicotine, an alkaloid contained in the tobacco plant, isobtained from the wastes of the cigar and cigarette manufacturing industries. It is adark, viscous liquid that has been used for years as a contact insecticide against soft-bodied sucking insects. It is highly toxic to most insects, but it is volatile and, therefore,nonpersistent. It is used as contact spray against sucking insects such as thrips,aphids, mealy bugs, and scale on vegetation. It is one of the most deadly and rapidlyacting poisons known for higher animals by inhalation or dermal application, especiallythrough the tongue or eye. Nicotine sulfate, one of the most common formulations, hasan LD50 value of 83 mg/kg. Nicotine is not a standard military item.


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(2) Petroleum and coal tar derivatives.

(a) Kerosene. Kerosene is used primarily as a solvent forinsecticides, but kerosene itself has considerable insecticidal effect. A refined, odorlessform is normally used as the carrier in household sprays. It has been used as a

mosquito larvacide. Kerosene is generally quite toxic to plants and can be dangerous toman if not properly handled. Ordinary and deodorized kerosene are available frommilitary standard stock.

(b) Fuel oils. Fuel oils (diesel oils) have been used extensively asmosquito larvicides. No. 2 diesel is the material generally used, often mixed with aspreading agent. The unmixed oil is a standard solvent for outdoor space sprays. It isavailable from military standard stocks.

(c) Summer oils. Summer oils are distillation fractions higher thankerosene which are employed in water emulsion on orchards and shade trees for

control of mites and scale insects. The summer oils are employed against these pestswhen the plants are in foliage.

(d) Dormant oils. Dormant oils are more highly sulfonated petroleumoils than are summer oils and are used against the same pests, but they can only beused safely when trees are dormant. They affect primarily the egg stage and also workwell on the crawler stage of scale insects. Neither summer nor dormant oils arestandard stock items.

c. Synthetic Organic Insecticides. The synthetic organic insecticides arerelatively new compounds. The first synthetic organic insecticide -- DDT -- wassynthesized in 1874, and its insecticidal properties were first recognized in 1939.During World War II, research in nerve gases led to the discovery of additionalcompounds that are effective insecticides.

(1) Chlorinated hydrocarbons. The chlorinated hydrocarbons arecharacterized by having a long residual of toxic material in the environment. They varywidely in their toxicity -- from aldrin and dieldrin, which are highly toxic, to methoxychlor,which has relatively low toxicity. The chlorinated hydrocarbons act upon the centralnervous system, causing death through respiratory failure. Changes in recent yearspertaining to pesticide legislation and registration have resulted in the cancellation orsuspension of use for all of the chlorinated hydrocarbons.

(2) Organophosphates. The organophosphates insecticides are generallymore toxic to animals than are the chlorinated hydrocarbons. However, theorganophosphates do not leave highly persistent residues on the treated plants andanimals and are less likely to accumulate in animal tissues. The physiological action ofthe organophosphates is the inhibition of the production of cholinesterase, an enzymeessential to the proper functioning of the central nervous system. Cholinesterase


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insufficiency causes spasm of the involuntary muscles, resulting in respiratory failureand death.

(a) Malathion. Malathion is a yellow to dark-brown liquid that is onlyslightly soluble in water and of limited solubility in petroleum solvents, but which can be

readily mixed with most organic solvents. It is a broad-spectrum insecticide, beingeffective against a wide range of pests including houseflies, cockroaches, andmosquitoes, many of which are resistant to chlorinated hydrocarbons. It has also beenrecommended for control of vegetation pests, sand flies, bedbugs, fleas, ticks, andstored product pests. Malathion is not as long lasting as the chlorinated hydrocarbons,but it is used as a residual insecticide. It is not toxic to plants at concentrations normallyused on vegetation, but it will damage ornamentals at concentrations used to controlflies. Because of its low toxicity to mammals (LD50 1,000-1,375 mg/kg), malathion hasbecome one of the most commonly used insecticides. An objection to malathion forhousehold use is its disagreeable odor.

(b) Diazinon. Diazinon is a pale to dark brown liquid that is readilysoluble or miscible in most organic solvents. It is much more toxic to both insects andanimals (LD50 76-108 mg/kg) than is malathion, but it is diluted to much lowerconcentrations. Diazinon is the insecticide of choice for controlling many householdinsects, particularly German cockroaches. It is also used extensively for fly control as aresidual spray, in sugar-bait formulations, and for impregnating fly cords. Diazinon hasa somewhat longer residual effect than malathion, but at strengths of equaleffectiveness, malathion is preferred for routine military use because of its lowermammalian toxicity. Diazinon is preferred over malathion in areas frequented bypeople, because of the offensive odor of malathion.

(c) Dichlorvos. Dichlorvos (also known commercially as DDVP orVapona) is a relatively new insecticide that has a short residual life, but is remarkablebecause of its high volatility. It gives off vapors slowly from impregnated resin stripsand is effective as a space insecticide. It is also added to dry and liquid fly baits to addquick knockdown and its toxic vapor aids in "clean out" applications on hard-to-reachinfestations of cockroaches and dog ticks. It is more toxic than diazinon, having an oralLD50 value of 56-80 mg/kg and a dermal LD50 value of 75-107 mg/kg.

(d) Naled. Naled (Dibrom) is an organophosphate insecticide that isclosely related chemically to dichlorvos. It is a contact and stomach poison with alimited amount of vapor toxicity. The principle military use of naled is as a fog for adultmosquitoes and flies. It is also effective, in a commercial form, as a bait or spottreatment for flies. The LD50 value of naled is 250 mg/kg.

(e) Chlorpyrifos. Chlorpyrifos (Dursban) is used in the militaryprimarily for control of mosquito larvae and cockroaches. It also offers good control ofturf pests such as chinch bugs and sod webworms. It has an LD50 value of 135-163mg/kg and may be irritating to the eyes.


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(3) Carbamates. The carbamates are organic sulfur compounds. Theyare esters of carbamic acid. They are similar to the organophosphate insecticides intheir physiological action, being inhibitors of the enzyme cholinesterase. In general,they have a shorter residual effect than the organophosphates. As insects continue todevelop resistance to the chlorinated hydrocarbons and the organophosphates, this

group of chemicals will play a role of ever-increasing importance in chemical pestcontrol.

(a) Carbaryl. Carbaryl (Sevin) is a moderately toxic (LD50 500-850mg/kg) insecticide which offers good control of mites, ticks, and fleas. It is highly toxicto bees and should be used with care if they might come in contact with it.

(b) Propoxur. Propoxur (Baygon) is considerably more toxic thancarbaryl; therefore, most military formulations contain only 1 or 2 percent. It isparticularly effective against German cockroaches resistant to diazinon. It is alsoeffective against ants, spiders, and many other household pests.

(c) Bendiocarb. Bendiocarb (Ficam) is a moderately toxic (LD50 143mg/kg) insecticide which is effective against cockroaches, crickets, fleas, ticks, ants,bedbugs, and other pests. This product is odorless and is registered for use inhospitals.

d. Toxicities of Insecticides. Table 1-1 summarizes the toxicities of the mostcommon insecticides. In interpreting this table, the following must be kept in mind.

(1) The data are not the result of laboratory tests and are subject to widevariations. They cannot be considered exact figures, but only relative values forpurposes of comparison.

(2) The test data were obtained from small animals (chiefly white rats) andcannot, therefore, be directly applied to humans.

1-7. REPELLENTS

a. General. Repellents are chemical compounds used as liquids, creams,aerosols, or solids to prevent biting or other annoyance by insects or other animal life.Personal protection from the bites of mosquitoes, biting flies, fleas, ticks, chiggers,leeches, and other pests may be obtained by the application of repellents to the skinand/or the clothing.

b. Use of Repellents. As one of several ways the individual may protecthimself in the absence of other pest control operations, the timely use of insectrepellents is extremely important. Frequently, when the threat of disease transmissionis the greatest, only individual protective measures are available.


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ORAL LD50 DERMAL LD50 INSECTICIDE (mg/kg) (mg/kg)

Inorganics

Lead Arsenic (N/S) 1,050 2,400

Botanicals

Nicotine Sulfate (N/S) 83 285Pyrethrum 1,500 1,880Rotenone (N/S) 50 -- 75 940

Chlorinated Hydrocarbons

Chlordane 335 -- 430 840 -- 690Lindane 88 -- 91 1,000 -- 900

Organophosphates

Chlorpyrifos 150 N/ADiazinon 108 -- 76 900 -- 455Dichlorvos 80 -- 56 107 -- 75Malathion 1,375 -- 1,000 4,444Naled 250 800

Carbamates

Carbaryl 100 N/APropoxur 850 -- 500 4,000Bendiocarb 143 N/A

Other Synthetics

Allethrin (N/S) 680 N/A

NOTES: Where two values are given, the first is for males and the second is forfemales (test animals).N/A denotes test data not available.N/S denotes nonstandard.

Table 1-1. Toxicities of common insecticides.


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c. Types of Repellents. Some repellents are more effective for some usesthan are others. There are several formulations in the military supply system.

(1) Personal use or skin application. Repellents for personal use areapplied directly to the skin. Usually, 2.5 ml of the cream rubbed between the hands and

spread evenly over the face, neck, hands, and other exposed skin areas offersprotection for up to 12 hours, depending upon the pest species concerned. Additionalrepellent may be spread on the clothing at the shoulders and other areas where thecloth fits tightly against the body. Be careful to keep the chemical out of the eyes. Thechemical is lost from the skin by abrasion, absorption, and evaporation. Theeffectiveness of the material is lost more rapidly (6 hours) in hot, humid climates whereprofuse sweating occurs. Repellents that are recommended for application on the skinmay also be applied by hand or by sprayer to the outside of the clothing, if desired.However, several special items have been developed for impregnation of clothing toeither repel or kill mites, insects, and other pests. The repellent for personal use isDEET (30% N, N-diethyl-m-toluamide), which provides protection against all types of

mosquitoes, other biting flies, and fleas. It is relatively effective against ticks andchiggers.

(2) Clothing application. Permethrin formulations are designed so thatclothing, bednets, tents, and tent liners can be dipped or sprayed with a solution of therepellent chemical. A desired quality of these formulations is that treated materials beable to withstand laundering or wetting without losing its repellent properties. Theprincipal requirement for a clothing treatment chemical for military use is the protectionof troops against chiggers, ticks, and leeches in many areas of the world. Detaileddirections for use of these materials vary with the specific item and with the type ofclothing being treated. Instructions issued by the local command surgeon should befollowed.

Section III. RODENTICIDES

1-8. GENERAL

Poisoning of rodents at military installations is normally undertaken withanticoagulants or zinc phosphides, both of which are standard rodenticides. Sodiummonofluoroacetate, a restricted use rodenticide that requires approval of the SurgeonGeneral for procurement and use, is a nonstandard item for emergency use. Thestandard rodenticides provide adequate rodent control under a wide range of conditions.Nonstandard items should be used only when standard items fail or are not available.

1-9. ANTICOAGULANTS

These rodenticides are chemicals that cause internal bleeding by reducing theclotting ability of the blood. Since all warm-blooded animals are affected in this manner,


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precautions should be taken to prevent humans, domestic animals, and pets fromeating baits containing anticoagulants. These chemicals are stable and are odorlessand tasteless to rodents in the concentrations used. A single feeding on bait containingan anticoagulant at the recommended concentration is not sufficient to cause death.Food baits or water solutions must be consumed over a period of several days before

they become effective. Even when weakened, rats and mice do not associate their lossof strength with their food supply. This means that the problem of bait shynesscommonly associated with "one-shot" poisons is largely overcome. Maximum kill isgenerally achieved between the fourth and ninth nights that poisoned bait is consumedby the rodent. Continuous baiting for two weeks (or longer) is often required to obtainsatisfactory control. To control house mouse populations, continuous baiting for amonth or more may be necessary because of the nibbling habits of mice. Bait shouldbe placed in a bait station or in a place that offers the rodent a protected feeding placeand protects the bait from domestic animals and the weather. Spoiling of the baitmaterial will, of course, depend on the type of food used and on climatic conditions. Drycereal baits remain in good condition much longer than meat or vegetable baits and are,

therefore, the foods of choice for use with anticoagulants. Baits should be replenishedbefore they are completely eaten to prevent the rodents from abandoning the feedingstations and to prevent infestation by stored products pests. Anticoagulants areprovided in two formulations -- a prepared material, ready for use, and concentrated foruse in the preparation of food baits or water solutions. The active ingredient may beone of the following chemicals: Diphacinone, Warfarin, Fumarin, Pival, or PMP.

a. Rodenticide, Anticoagulant, Ready Mixed. This formulation is aready-to-use bait containing an anticoagulant chemical, rolled oats, sugar, and mineraloil (to increase its acceptability). A red dye has been added to distinguish it fromordinary rolled oats. The item is used directly from its container without further mixing.

b. Rodenticide, Anticoagulant, Universal Concentrate. This item is aconcentrate that can be mixed with food, bait, or water. It consists of a warm solubleanticoagulant chemical, sugar (to make water solutions more palatable), sodiumbenzoate (a preservative), and a complexing agent to hold the anticoagulant in solution.Glass, plastic, or paper water-holding containers may be used for dispensing. Poisonedwater is especially effective where water is scarce. The use of poisoned water andpoisoned baits simultaneously will increase the effectiveness of the control program.

1-10. ZINC PHOSPHIDE

Zinc phosphide is a highly poisonous black powder consisting of about 75percent zinc phosphide and 25 percent antimony-potassium tartrate. The lattercompound is an emetic that has been added to prevent accidental poisoning of humansand domestic animals. One feeding of poisoned bait containing 0.1 percent zincphosphide is sufficient to kill a rodent. A single sublethal dose can cause bait shynessfor baits containing this poison. Therefore, an acceptable food must be used as bait toachieve successful control. Although zinc phosphide has a disagreeable odor tohumans, it is not repellent to rats and may even attract them.


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Section IV. FUMIGANTS AND FUNGICIDES

1-11. GENERAL

Fumigants are poisons that are used in gaseous form to kill insects, rodents, andother pests via the respiratory tract. The use of fumigants is generally limited toenclosed spaces or tightly sealed containers. The gases used as fumigants penetratecracks, crevices, and tightly packed materials, providing a fast, direct, and effective wayof killing most stages of animal life. Because of their highly toxic nature, fumigants maybe applied only by trained and certified personnel. Standard fumigants may be furtherclassified according to their use as stored product fumigants, structural fumigants, andsoil fumigants.

1-12. STORED PRODUCT FUMIGANTS

Aluminum phosphide (Phostoxin), upon exposure to atmospheric moisture,releases a gas known as hydrogen phosphide (PH3) or phosphine. It has an odor likegarlic and can penetrate even closely packed commodities. It is used for fumigation ofstored products indoors or outdoors under polyethylene or vinyl-coated tarpaulins,which must be sealed to the floor or ground. It cannot be used with cloth or canvastarpaulins. It is also effective for the treatment of stored products in sealed boxcars orhopper cars, whether static or rolling. Other military uses include the fumigation of rawagricultural commodities, with or without tarpaulins, and structural or space fumigationfor pests of stored products and dry wood. Hydrogen phosphide gas can explode ifunder vacuum and must be used only under atmospheric conditions. It will leavetreated material and the fumigated stack within one hour with normal ventilationprocedures. Under specific atmospheric conditions involving moisture condensation onthe item being fumigated, phosphine will corrode copper or products containing copper.For this reason, such items must not be placed in an area or covered in a manner thatmay induce condensation. In accordance with EPA label instructions, aluminumphosphide must not be used in such a manner as to allow the pellets, tablets, orunreacted residues (ash) to come in contact with any processed food. With thisexception, PH3 will not combine in any form to produce a food residue. Phosphine ishighly toxic to all forms of human, insect, and other animal life. For this reason,application should be closely supervised by the engineer or medical entomologist.Personnel engaged in the application of this fumigant must be certified and speciallytrained. Aluminum phosphide is available in tablet or pellet form.


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MD0173 1-13

Section V. HERBICIDES

1-13. GENERAL

Herbicides are chemicals used to kill or control the growth of weeds. A weed

may be defined as any noxious plant, that is, one whose presence is unwanted andwhich interferes with the growth of desirable plants. Therefore, the term is a relativeone. Some plants that may be desirable in one place may be very noxious in others.Examples are Bermuda grass, Johnson grass, oak trees, persimmon trees, and manykinds of vines. Weed control is an Army Engineer Corps, rather than an Army MedicalCorps, responsibility. Therefore, Army Medical Department interest in herbicides isconfined primarily to the areas of toxicity and environmental impact.

1-14. CLASSIFICATION OF HERBICIDES

Herbicides may be classified as to their selectivity (principal use) or to their

biological action.

a. Classification According to Selectivity.

(1) Selective herbicides. Selective herbicides kill certain weed specieswithout seriously injuring the desirable plants among which they are growing. Thereasons for selectivity in some combinations of weeds and desirable plants are known.Annuals (seed-bearing plants which mature in one season) growing among perennials(plants that live more than 2 years) can be killed by sprays from which the perennialscan recover. The reasons for selectivity in other situations are not known. Certainherbicides kill broad-leaved weeds, others kill grasses, and some kill both.

(2) Nonselective herbicides. Nonselective herbicides kill vegetation withlittle discrimination. Some species of plants, however, escape. Some are resistant;some have roots that extend below the depth of chemical penetration; and someshallow-rooted plants reinfest after the chemical has leached below the surface layer.

b. Classification According to Biological Action.

(1) Contact herbicides. Contact herbicides kill tissues that are wetted withspray. Whether the plant dies or recovers depends upon whether it has a protectedgrowing point. Perennials usually have underground buds that will regrow.

(2) Growth regulator herbicides. Growth regulator herbicides act like planthormones. They are absorbed through the leaves, stems, or roots and are translocatedthrough the vascular system to other parts of the plant. They accumulate mostly inareas of rapidly dividing cells, upsetting the normal metabolism of the plant and causingdeath of the cells.


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(3) Soil herbicides. Soil herbicides are those that are applied to the soil,absorbed by the roots, and translocated to other parts of the plant.

(4) Soil-sterilant herbicides. Soil-sterilant herbicides make the soilincapable of supporting higher plant life; however, they do not necessarily kill all life,

such as fungi, bacteria, and other microorganisms. Toxic effects may persist for only ashort time or for years, depending upon the chemical, the soil, and the rate ofapplication.

(5) Pre-emergence herbicides. Pre-emergence herbicides are thoseapplied to the soil before the foliage of the weed appears above the soil surface. Theymay kill by contact or they may be translocated from the point of entry into roots, stems,or leaves. Some inhibit photosynthesis, while others effect growth processes such ascell division and elongation.

1-15. STANDARD MILITARY HERBICIDES

The standard herbicides on the military stock list are shown in Table 1-2. Itshould be noted that, although these pesticides are standard items, they may beprocured and used only by trained, certified personnel. They are of concern to AMEDDagencies primarily from the standpoint of toxicity. Table 1-2 lists the standardherbicides on which data are available, showing the name, the type of growth for whichused, principal mode of action, and toxicity of each chemical. Additional information onherbicides is contained in TM 5-629, Weed Control and Plant Growth Regulation.Although the dermal toxicities of the herbicides are low in general, many of them areirritating to the eyes, nose, throat, and skin. Herbicide labels, required on all herbicidecontainers, list the hazards of each chemical and warn operators or consumers toprotect themselves from such hazards. Any person having occasion to handle aherbicide should, as with any other pesticide, carefully read the information on the label.

Continue with Exercises


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Use or LD50 DermalName Used to Control Action1 (Mg/Kg) Rating Toxicity

Bromacil Noncropland grass and

broadleaf weeds SS 5,200 Low Moderate

Cacodylic General control of established 830 --Acid weeds C 1,350 Moderate Low

Dalapon Annual grasses; cattail and rushes, 3,860 --pine and cedar GR; S 9,330 Low Low

Dicamba Noncropland grasses andbroadleaf weeds; trees; some 1,040 --brush species GR 2,900 Moderate

400 --Diquat Aquatic weeds C; Aq 500 High 500

3,400 -- ModerateDiuron General vegetation SS; P 7,500 to low Low

DSMA Noncropland Johnson grass 1,800--cocklebur; many annual grasses C 2,800 Moderate None

Monuron General vegetation; oak SS 3,600 Moderate Low

Picloram Noncropland annual, perennial

broadleaf weeds; trees; woodyplants GR; SS 8,200 Low 4,000

Silvex Annual and perennial broadleafweeds, woody plants; 375 --some aquatics GR 1,200 Moderate Low

Simazine General nonselective weedcontrol P; S 5,000 Moderate None

2,4-D Annual and deep-rooted 300 High toweeds; trees GR 1,000 Moderate Low

2,4,5-T Annual and deep-rooted 300 --weeds; brush GR 500 High Low

1Legend: C = contact; S = soil; GR = growth regulator; P = preemergence; S = soilSS = soil sterilant

Table 1-2. Standard military herbicides and their characteristics.


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EXERCISES, LESSON 1

INSTRUCTIONS: Answer the following exercises by marking the lettered response thatbest answers the exercise, by completing the incomplete statement, or by writing theanswer in the space provided at the end of the exercise.

After you have completed all of these exercises, turn to "Solutions to Exercises"at the end of the lesson and check your answers. For each exercise answeredincorrectly, reread the material referenced with the solution.

1. Match the following:

a. Pesticide ____________ (1) Anticoagulant.

b. Insecticide __________ (2) Methyl alcohol.

c. Rodenticide _________ (3) Used to kill any undesirableorganism.

d. Fumigant ___________ (4) Used to kill various arthropods.

e. Herbicide ___________ (5) Always found in gaseous form.

(6) Used to kill unwanted plants.

(7) Enters the pest through therespiratory system.

(8) Only one in standard inventory.

2. Standard military pesticides are chemicals that may be:

a. Procured and used by all military personnel.

b. Procured through military supply channels.

c. Purchased locally.


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3. Controlled pesticides may be used only:

a. In restricted areas.

b. Against restricted types of pests.

c. By or under the supervision of trained and certified personnel.

d. Overseas, during emergency situations.

4. Which of the following pesticides is more toxic from the standpoint of absorptionthrough the skin?

a. Pyrethrum.

b. Nicotine.

c. Dichlorvos.

d. Propoxur.

5. A pesticide having an LD50 of 300 mg per kg of body weight is considered tohave _______________ toxicity.

a. High.

b. Low.

c. Moderate.


a. Stomach poison _________ (1) Causes internal bleeding oftarget pests.

b. Contact poison _________ (2) Can enter through the body wall.

(3) Must have a low LC50 value.c. Anticoagulant __________

(4) Must be eaten to be effective.


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7. Classify the following standard insecticides by indicating in the space besideeach the letter from the right hand column corresponding to the chemical type.

a. Pyrethrum _________ (1) Inorganic.

b. Sulfur __________ (2) Natural organic.

c. Naled __________ (3) Chlorinated hydrocarbon.

d. Dichlorvos _________ (4) Organophosphate.

e. Boric acid _______ (5) Carbamate.

f. Nicotine _________

g. Dursban ____________

h. Baygon _____________

i. Carbaryl _____________

j. Malathion ____________

k. Chlordane ____________

l. Diazinon ______________

8. The standard insect repellent for skin application is:

a. BHC.

b. DEET.

c. DDT.

d. None of the above.


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9. Which fumigant is currently used for the control of pests of stored food products?

a. Diethyl toluamide.

b. Aluminum phosphide.

c. Aluminum chlorhydrate.


10. Chemicals which kill certain kinds of plants while not seriously injuring others areknown as _____________________ herbicides.

a. Choosy.

b. Discriminating.

c. Selective.

d. Picky.


Types of Herbicides: Characteristics:

a. Preemergence _____ (1) Act like hormones.

b. Growth regulator ______ (2) Enter through respiratory system.

c. Soil sterilant ______ (3) Make soil unable to support life.

d. Contact ______ (4) Require repeated treatment.

(5) Kill tissues wetted with spray.

(6) Applied before foliage appears.

Check Your Answers on Next Page


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SOLUTIONS TO EXERCISES, LESSON 1

1. a(3) (para 1-1)b(4) (para 1-1a)c(1) (para 1-9)

d(7) (para 1-11)e(6) (para 1-1d)

2. b (para 1-2b)

3. c (para 1-2b)

4. c (para 1-4a;Table 1-1)

5. c (para 1-4a(3))

6. a(4) (para 1-5a)b(2) (para 1-5b)c(1) (para 1-9)

7. a(2) (para 1-6b(1)(a),Table 1-1)b(1) (para 1-6a)c(4) (Table 1-1)d(4) (Table 1-1)e(1) (para 1-6a)f(2) (para 1-6b(1)(b))g(4) (para 1-6c(2)(e))h(5) (para 1-6c(3)b)i(5) (Table 1-1)

j(4) (Table 1-1)k(3) (Table 1-1)l(4) (Table 1-1)

8. b (para 1-7c(1))

9. b (para 1-12)

10. c (para 1-14a(1))

11. a(6) (para 1-14b(5))b(1) (para 1-14b(2))c(3) (para 1-14b(4))d(5) (para 1-14b(1))

End of Lesson 1


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MD0173 2-1

LESSON ASSIGNMENT

LESSON 2 Pesticide Mixing and Calculations.

LESSON ASSIGNMENT Paragraphs 2-1--2-14.


2-1. Identify the reasons for concentrated anddiluted forms of pesticides.

2-2. Identify the four usable pesticide formulationsand their components.

2-3. Determine the amount of pesticide of a given

concentration required to prepare a usableformulation of a desired concentration.



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Section I. PESTICIDE FORMULATIONS

2-1. TECHNICAL GRADE PESTICIDES

A technical grade pesticide is the basic toxic ingredient in its purest commerciallyavailable form. This material is rarely chemically pure. Technical grade diazinon, forexample, contains only about 94 to 97 percent of the active chemical. However,technical grade pesticides are, in general, much too toxic for safe handling in the field.Standard military pesticides are generally technical grade pesticides that have beendiluted with appropriate carriers or diluents.

2-2. REASONS FOR PESTICIDE MIXING

The concentrated forms of pesticides (restricted use) included on the militarystock list, while generally less toxic than technical grade materials, are nevertheless

highly concentrated in many cases. Examples are carbaryl, 80% powder; naled, 85%solution concentrate; and malathion, 95% solution concentrate. Some of thesechemicals must be diluted before application, for obvious reasons. Such strongformulations would pose a severe hazard, not only to man, but also to nontargetorganisms such as fish and other wildlife, domestic animals, beneficial insects(honeybees, predators, etc.), agricultural crops, ornamental plants, and other desirableforms of life. If safety were the only consideration, it would be desirable to issue everypesticide in a ready-mixed, ready-to-use formulation. For those pesticides that areconsidered general use items, this is the case. These items are prepared for individualand small-unit use and are in formulations of very low concentrations, very smallquantities, or both. However, there are valid reasons for issuing pesticides inconcentrated form for further dilution in the field.

a. Economy in Shipping. Requirements for shipping and storing pesticidesare more stringent than are those for storing and shipping the diluents that are used todilute them to a strength that is safe for application. Moreover, the diluent is oftenavailable from local sources and need not be shipped. For example, a 55-gallon drumof 95% malathion solution concentrate, when mixed with No. 2 fuel oil, will provideenough active material for approximately 870 gallons of 6% malathion spray for outdoorspace treatment against mosquitoes. If this amount of spray were mixed prior toshipping, it would require 16 times as much shipping space and weight.

b. Flexibility in Application. Using concentrated pesticides to preparediluted mixtures enables the pest control operator to vary the strength according to thetarget pest, the type of equipment used, and the rate of application.

2-3. DUSTS

A dust is a dry mixture that usually consists of an active pesticide mixed with talc,clay, or some other inert powder used as a diluent, or carrier. Dusts are usually the


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lowest in cost, easy to apply, nonstaining, nontoxic to plant life, and generally not readilyabsorbed through the skin. They may be dangerous if inhaled into respiratorypassages. Since they are dry, they are the preferred formulation for use aroundelectrical connections. Due to their small particle size, they can be used to penetratesmall cracks and crevices. Two disadvantages of dusts are that they do not adhere well

to vertical surfaces and they are easily removed by wind and rain.

2-4. GRANULES

Granules are pellets varying from 16 to 30 mesh in size. The granules areusually impregnated with 5 to 50 percent of the toxicant. The carrier is generallybentonite, although vermiculite has been used. The granular form of insecticide isparticularly desirable in mosquito breeding areas covered by heavy vegetation, which isnot easily penetrated by liquid sprays. In mosquito control work, the granules may beapplied to large breeding sites by aircraft using special dispersing equipment.Backpack sprayers may be used for treating smaller breeding sites.

2-5. SUSPENSIONS

Suspensions are liquid formulations. They are prepared by diluting waterwettable powders with water and thoroughly mixing. A water wettable powder is a toxicingredient blended with an inert dust to which a wetting agent -- usually a soap ordetergent -- is added to facilitate mixing the powder with the water. This forms asuspension in which the fine particles are suspended -- not dissolved -- in the water.Suspensions require constant agitation during application to prevent solid particles fromsettling to the bottom of the sprayer. They are also more prone to clog the nozzles ofsprayers. These characteristics are the principal disadvantages of suspensions. Themajor advantage of the suspension is the low-cost and easily obtainable diluent --water. Suspensions are also relatively safe to apply since they are generally not easilyabsorbed through the skin and will not cause burning of plant foliage. Suspensionsusually have less odor than solutions or emulsions because of the water diluent, asopposed to an organic solvent. They are especially valuable for treating outbuildings,adobe, concrete, and thatch structures because the active material is deposited on thesurface. Solutions and emulsions, on the other hand, tend to penetrate such materialsand lose much of their residual effectiveness.

2-6. SOLUTIONS

A solution is a liquid formulation consisting of a solution concentrate dissolved ina diluent or solvent. The ideal solution would be one using water as the solvent, forreasons of economy as well as convenience. However, most of the synthetic pesticidesrelatively insoluble in water. Therefore, the solvents most commonly used are No. 2fuel oil (used in domestic heating), diesel oil, or kerosene. Other organic solvents mayalso be used. The solvent selected must be one in which the concentrate is soluble.An advantage of the solution is that constant agitation is not necessary, which facilitatesthe use of spraying equipment. It is effective as a contact insecticide, as the oil base


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easily wets and penetrates the insect cuticle (outer covering). In residual spraying, thesolvent evaporates from treated surfaces, leaving a deposit of the insecticide inrelatively pure form. Disadvantages of solutions are that they are readily absorbedthrough the skin; the solvents are flammable and relatively expensive; they stain; andthey are, in general, toxic to vegetation.

2-7. EMULSIONS

Emulsions are prepared by diluting emulsifiable concentrates with water andthoroughly mixing. The emulsifiable concentrate is a concentrated solution of the toxicagent in a solvent to which an emulsifying agent (wetting agent, such as soap or adetergent) has been added. The emulsifying agent enables the small droplets ofsolvent carrying the toxicant to remain dispersed through the water, much like the fatglobules in homogenized milk. The emulsion, like the solution, need not be constantlyagitated. This advantage, combined with that of a cheap, readily available diluent(water), makes the emulsion a commonly used pesticide formulation in the Army.

Emulsions are similar to solutions in their effects on insects and they can be used formost residual spraying. They do not usually stain surfaces. Their principaldisadvantages are that they are readily absorbed through the skin and that they may betoxic to plants.

2-8. SUMMARY

a. Figure 2-1 summarizes the basic constituents which combine to form a dustor suspension.

(1) Dust -- a technical grade insecticide plus an inert carrier.

(2) Suspension -- an insecticidal dust plus a wetting agent plus water.

b. Figure 2-2 summarizes the basic constituents that combine to form asolution or emulsion.

(1) Solution -- a solution concentrate consisting of a technical gradeinsecticide and a solvent, plus a diluent.

(2) Emulsion -- an emulsifiable concentrate consisting of a solutionconcentrate and an emulsifying agent, plus water).

c. The preparation of wettable powders and emulsifiable concentrates isaccomplished by the manufacturer before the pesticides are procured by the DefenseSupply Agency. Mixing by using personnel is normally limited to mixing an appropriatediluent with standard pesticides, issued through military supply channels, in one of thefollowing forms:

(1) Powders.


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(2) Wettable powders.

(3) Solutions.

(4) Solution concentrates.

(5) Emulsifiable concentrates.

Figure 2-1. Formulation of dusts and suspensions.


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Figure 2-2. Formulation of solutions and emulsions.


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MD0173 2-7

Section II. PESTICIDE MIXING CALCULATIONS

2-9. IMPORTANCE OF ACCURATE CALCULATIONS

It is difficult to overemphasize the importance of making accurate calculationseach time a pesticide is mixed. There are several reasons for emphasizing thisimportance.

a. Safety. If a formulation is prepared with too high a working concentration,human lives and other nontarget organisms may be endangered.

b. Effectiveness. If a formulation has too low a working concentration, thecontrol program may be a failure and insects may develop resistance to the pesticide.In addition, a repeat application may be necessary, thereby increasing the totalexposure to humans and other nontarget animals.

c. Economy. Pesticide concentrates are expensive. If calculations in mixingare not precise, not only do we run the risks cited in paragraphs a and b above, but wealso may needlessly waste toxic materials. Although the cost may not be great for anyone given error, the cumulative expense due to error may be enormous on an Army-wide basis.

2-10. WEIGHT/WEIGHT OR VOLUME/VOLUME CALCULATIONS

a. General. If we were mixing pure technical grade toxicants with diluents,mixing problems would be simple. We would merely have to mix, for example, 2pounds of toxicant with 98 pounds of diluent (or 2 gallons with 98 gallons) to obtain a 2percent mixture. In practice, however, our calculations are never quite so simple. Weare not necessarily mixing 100 pound or 100-gallon quantities, and our concentrates arenever 100 percent pure. Therefore, we use formulas that simplify our work as much aspossible. In order to use the formula, there are certain basic elements of information wemust have. The following must be obtained from the pesticide label:

(1) The name of the active ingredient (toxicant), its concentration, and itsform (carbaryl, 80% powder; malathion, 95% solution concentrate; etc.).

(2) The type formulation to be prepared (dust solution, emulsion, etc.) andthe diluent to be used.

(3) The concentration of toxicant desired in the final formulation (1%, 2%,05%, etc.).

(4) The quantity of final formulation required (5 gallons, 100 pounds, etc.).


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b. Calculation. The following sample problems will illustrate the derivationand use of the formula for mixing liquid concentrates with liquid diluents or solid(powder) concentrates with solid (powder) diluents:

(1) Problem #1. 55 gallons of 1% diazinon emulsion are to be prepared

using diazinon, 48% emulsifiable concentrate and water. How many gallons of theconcentrate are required?

(a) Figure 2-3 illustrates the problem graphically.

Notation:

Q = Quantity of concentrate in gallons or pounds (must be same units as A).

C = Concentration of toxicant in the concentrate in percent.A = Amount of final formulation desired in gallons or pounds (must be same

units as Q).S = Strength of final formulation in percent of active ingredient.

Figure 2-3. Volumetric calculations.

(b) Computation. The one element that will remain constantthroughout the problem is the actual amount of toxicant involved. When we dilute apesticide, we do not change the amount of toxicant. We merely add enough diluent so

that the final formulation will consist of the desired percentage of toxicant. The amountof toxicant in either the concentrate or the final solution is determined by multiplying theamount of concentrated or formulation by the percentage of toxicant. Thus:


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MD0173 2-9

Amount of toxicant in concentrate = Q X C (Q X 48%)

Amount of toxicant in formulation = A X S (55 gal X 1%)

The amount of toxicant is constant; therefore,

A X SQ X C = A X S, or Q = .

C

Substituting the known values for the letters, we can solve forQ as follows:

55 gal X 0 .01Q = = 1.146 gal concentrate

0.48

(c) To the 1.1 (1.146 rounded) gallons of 48% diazinon emulsifiableconcentrate, we must add 53.9 gallons of water to prepare the desired 55 gallons of 1%emulsion.

(2) Problem #2. In preparing dusts by diluting concentrated powders withinert talc, the procedure is identical, but we are dealing with weight instead of volume.Thus, to determine the amount of 80% carbaryl powder required to prepare 10 poundsof 5% dust.

(a) C = 80% (.80)A = 10 lbS = 5% (.05)

A X S 10 X 0.05(b) Q = = = 0.625 lb (10 oz)

C 0.80

(c) To the 10 ounces of 80% carbaryl powder, we must add 9pounds, 6 ounces of inert talc or other carrier to prepare the desired 10 pounds of 5%dust.

2-11. WEIGHT/VOLUME CALCULATIONS

a. General. From time to time the pest control operator will be required toprepare suspensions, by mixing wettable powders with water. Because a given volumeof powder is considerably lighter than an equal of liquid, calculation by thevolume/volume method is not accurate. Therefore, we use the weight/weightcalculation, converting the volume of liquid to weight so that both values are expressedin units of weight. A weight/volume calculation, then, is a calculation using a constant or


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conversion factor to convert the volume of the liquid to weight. The formula for aweight/volume calculation is:

A X S X DQ = , where D = Density of the diluent .

C

If the dilutent is water, the density is 8.34 pounds per gallon. If a diluentother than water is used, the density of that particular diluent should bedetermined for most accurate results. A few common diluents and theirdensities are the following:

(1) Acetone (6.5 lb/gal).

(2) Fuel oil No. 2 (7 lb/gal).

(3) Kerosene (6.4 to 6.6 lb/gal).

b. Calculation. The following sample problem will illustrate the use of theformula for mixing solid (powder) concentrates with liquid diluents.

(1) Problem. 5 gallons of 2% carbaryl suspension are to be preparedusing carbaryl 80% wettable powder and water. How many pounds of concentrate arerequired?

(2) Figure 2-4 illustrates the problem graphically.

(3) Computation.

A X S X D 5 gal X .02 X 8.34 lb/galQ = = = 1.04 pounds

C 0.80 concentrate

This amount (1 pound) of concentrate is placed in a 5-gallon container andenough water is added to fill the container (total mixture = 5 gallons).


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Q = Quantity of concentrate in pounds.C = Concentration of Q in percent.A = Amount of final formulation in gallons.S = Strength of final formulation in percent.D = Density of diluent in pounds per gallon.

Figure 2-4. Weight/volume calculations.

c. Uniformity of Procedure. For the sake of uniformity, it is most convenientto use one formula for all calculations -- weight/weight, volume/volume, andweight/volume. The formula is:

A X S X DQ =

C

If Q and A are expressed in the same units (either pounds or gallons),D = 1. If Q is expressed in pounds and A in gallons, D = the density ofthe diluent (8.34 lb/gal if the diluent is water).


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MD0173 2-12

Section III. PESTICIDE APPLICATION CALCULATIONS

2-12. DETERMINING REQUIREMENTS

a. General. Mixing and diluting pesticides to required strengths and quantitiesis only one step in pest control operations. Before preparing the formulations, we mustdetermine the quantities and strengths that are required for our particular task. Pestcontrol operations do not fall within the scope of this subcourse; however, determiningrequirements for pesticides will be discussed in this section.

b. Recommendations. Technical Information Memorandum (TIM) 24,Contingency Pest Management Pocket Guide, has a comprehensive list ofrecommended pesticides, strengths, and rates of application for attacking variousinsects and other pests. However, the pesticide label itself is the ultimate source ofguidance on pesticide application rates. Depending upon the type of application

(agricultural use; household use; outdoor control of flies, mosquitoes, mites; etc.) theunits of measure may vary.

c. Requirements. The amount of final formulation depends upon two factors:

(1) The area to be treated.

(2) The rate of application.

d. Computaton. The amount of formulation required is determined bymultiplying the area in acres or square feet (usually in thousands) by the number ofgallons or pounds of final formulation per acre or square feet (1,000 square feet).

2-13. CALCULATING AREAS

a. Area in Square Feet. The area of a given tract of land, household space,or storage space is determined by multiplying the length by the width. For example, afield 300 feet long and 150 feet wide contains 45,000 square feet (300 X 150 = 45,000).If a given pesticide should be applied at the rate of 1 gallon per 1,000 square feet, thetotal amount required for this field would be 45 gallons (45,000/1,000 = 45). Obviously,the above calculation applies only to a rectangle. Other simple formulas for calculatingthe areas of common figures follow.


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MD0173 2-13

(1) Triangle.

I x hArea =

2

(2) Trapezoid:

(2) Trapezoid.

I1 + I2

Area =______ = h2

(2) Trapezoid: (I1 and I2 must be parallel)

(3) Areas more complicated than previously shown can be broken downinto smaller areas (see below) or, if they are quite complex, it may be necessary to havetheir areas computed by a professional surveyor.

Triangle and trapezoid Figure broken into atriangle and a trapezoid.

b. Areas in Acres. An acre contains 43,560 square feet. Therefore, once anarea is determined in square feet, it may be divided by 43,560 to obtain its area inacres. For example, a field 400 feet long and 400 feet wide contains 160,000 squarefeet (400 X 400 = 160,000). 160,000 square feet divided by 43,560 square feet per acreis equal to about 3.67 acres.


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MD0173 2-15

Figure 2-5. Standard pesticide label.


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MD0173 2-16

b. Pounds of Toxicant per Acre and Pounds of Diluted Dust Per AcreComputation. If the recommendations for applying a pesticide in dust form specify thenumber of pounds of toxicant per unit area (per acre or per 1,000 square feet), theamount of diluted dust to be applied per unit area (in the same units) may bedetermined as follows.

(1) Pounds of toxicant per unit area = pounds of diluted dust per unit areaX percent toxicant in diluted dust.

Lb toxicant/acreTherefore: lb diluted dust/acre = - .

% toxicant

(2) Example: How many pounds of 5 percent dust are required per acre ifthe recommended rate of application is 10 pounds of toxicant per acre?

10 lb toxicant/A = 200 lb diluted dust/A0.05

c. Pounds of Toxicant per Acre and Gallons of Diluted Spray per AcreComputation. If the recommendations for applying a pesticide in diluted spray formspecify the number of pounds of toxicant per unit area, the amount of diluted spray ingallons may be determined as follows.

(1) Pounds of toxicant per unit area = pounds of diluted spray (gal X 8.34lb/gal) per unit area X percent toxicant in diluted spray.

lb toxicant/AThen: gal diluted spray/A X 8.34 lb/gal =

% toxicant

lb toxicant/ATherefore: gal diluted spray/A = .

% toxicant X 8.34 lb/gal

(2) Example: How many gallons of 6 percent emulsion are required peracre if the recommended rate of application is 0.3 pounds of toxicant per acre?

0.3 lb toxicant/A = 0.6 gal diluted spray/A0.06 X 8.34 lb/gal

Continue with Exercises


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MD0173 2-17

EXERCISES, LESSON 2

INSTRUCTIONS: Answer the following exercises by marking the lettered response thatbest answers the exercise, by completing the incomplete statement, or by writing theanswer in the space provided at the end of the exercise.

After you have completed all of these exercises, turn to "Solutions to Exercises"at the end of the lesson and check your answers. For each exercise answeredincorrectly, reread the material referenced with the solution.

1. A pesticide in its purest commercially available form is known as:

a. Pure grade.

b. Technical grade.

c. Commercial grade.


2. Select the reason(s) for mixing pesticides in the field? (You may select morethan one answer).

a. To economize in shipping.

b. Because it is more hazardous to ship ready-mixed formulations.

c. Because mixing facilities are better in the field than in garrison.

d. To give the operator flexibility in preparing strengths to meet specificrequirements.

3. Which of the following are advantages of dusts? (You may select more than oneanswer)?

a. They adhere well to vertical surfaces.

b. They are not readily absorbed through the skin.

c. They can be used around electrical connections.

d. They are weather resistant.

e. They can penetrate small cracks and crevices.


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MD0173 2-18

4. Suspensions are made by mixing which of the following?

a. A water wettable powder and an organic solvent.

b. A dust and a wetting agent.

c. A dust and water.

d. A wettable powder and water.

e. A suspendable concentrate and water.

5. A disadvantage of the suspension is that it:

a. Is easily absorbed through the skin.

b. Is expensive.

c. Must be constantly agitated.

d. Penetrates building materials, losing much of its residual effect.

6. A solution consists of:

a. A solution concentrate mixed with water.

b. An emulsifiable concentrate mixed with oil.

c. A solution concentrate and diluent in which the concentrate is soluble.

d. A wettable powder and an organic solvent.


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MD0173 2-19

7. Which of the following are disadvantages of the solution?

a. It usually requires an expensive solvent.

b. It is usually flammable.

c. It requires constant agitation.

d. It has little effect as a contact spray or residual spray.

e. It is easily absorbed through the skin.

8. An emulsion consists of:

a. An emulsifying agent and water.

b. Technical grade pesticide and an emulsifying agent.

c. An emulsifiable concentrate and a petroleum solvent.

d. An emulsifiable concentrate and water.

9. Which of the following are advantages of the emulsion?

a. It uses an inexpensive diluent.

b. It need not be constantly agitated.

c. It is not readily absorbed through the skin.

d. It has both contact and residual effect.

e. It is nontoxic to plants.

10. Is the following statement true or false? "It is better to mix pesticides too weakthan too strong in order to prevent a hazard to human lives and other nontargetorganisms."

a. True.

b. False.


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MD0173 2-20

11. How much 80% carbaryl powder is required to prepare 16 pounds of 5% dust?

a. 10 lbs.

b. 5 lbs.

c. 1 lb.


12. How much toxic material is present in the above formulation?

a. 8 lbs.

b. 0.8 lbs.

c. 6.4 lbs.


13. How much chlopyrifos 72% emulsifiable concentrate is required to make 100gallons of 2% emulsion?

a. 2.8 gal.

b. 5.6 gal.

c. 3600 gal.


14. How much toxicant is present in the above formulation?

a. 3.6 gal.

b. 5.6 gal.

c. 2 gal.



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MD0173 2-21

15. How much carbaryl 80% wettable powder is required to prepare 100 gallons of2% suspension?

a. 20.8 lbs.

b. 10.4 lbs.

c. 41.6 lbs.


16. How many square feet are there in a room 50 feet long and 35 feet wide?

a. 175.

b. 1750.

c. 85.


17. If a pesticide label recommends application at the rate of 1 gallon per 1,000square feet, how many gallons are required for the room in item 16 above?

a. 0.18 gal.

b. 1.75 gal.

c. 0.85 gal.


18. What is the area, in acres, of a field 385 feet long and 170 feet wide?

a. 4.5 acres.

b. 15 acres.

c. 1.5 acres.



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MD0173 2-22

19. If the recommended rate of application of a 5% dust is 1.5 pounds of toxicant peracre, how many pounds of diluted dust are required to treat the field in item 18?

a. 45 lbs.

b. 30 lbs.

c. 3.0 lbs.


20. If the recommended rate of application of a 2% spray is 10 pounds of toxicant peracre, how many gallons of spray are required to treat the field in item 18?

a. 60 gal.

b. 90 gal.

c. 105 gal.


Check Your Answers on Next Page


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MD0173 2-23

SOLUTIONS TO EXERCISES, LESSON 2

1. b (para 2-1)

2. a (para 2-2a)

d (para 2-2b)

3. b, c, e (para 2-3)

4. d (para 2-5)

5. c (para 2-5)

6. c (para 2-6)

7. a, b, e (para 2-6)

8. d (para 2-7)

9. a, b, d (para 2-7)

10. b (para 2-9) (Mixing a formulation too weak is equally, if not more, undesirable.If a formulation is too weak, the program may be a failure and require a repeatapplication and thereby increase the exposure to nontarget species.)

11. c (paras 2-10b(2),2-11c) A X S X D 16 lb X 0.05 X 1Q = = = 1 lb

C 0.80

12. b (para 2-10b(1)(b))Amt toxicant = A X S = 16 lb X 5% = 0.8 lb, orAmt toxicant = Q X C = 1 lb X 80% = 0.8 lb

13. a (paras 2-10b(1),2-11c)

A X S X D 100 gal X 0.02 X 1Q = = = 2.778 gallons (rounds to 2.8)

C 0.72

14. c (para 2-10b(1)(b))Amt toxicant = A X S = 100 gal X 2% = 2 gallons, orAmt toxicant = Q X S = 2.8 gal X 72% = 2.016 gallons (rounds to 2)


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MD0173 2-24

15. a (para 2-11b)

A X S X D 100 gal X 0.02 X 8.34 lb/galQ = = = 20.8 lb

C 0.80

16. b (para 2-13a) 50 ft X 35 ft = 1,750 ft2

17. b (para 2-13a)

1 gal/ft2 X 1,750 ft2

= 1.75 gal1,000

18. c (para 2-13b)65,450 ft2

385 ft X 170 ft = = 1.50 A43,560 ft2 A

19. a (para 2-14b)1.5 lb toxicant/A

= 30 pounds diluted dust/A0.05 toxicant in diluted dust

30 lb/A X 1.5A = 45 lb diluted dust

20. b (para 2-14c)

10 lb/A = 60 gal/A

(0.02 X 8.34 lb/gal)

60 gal/A X 1.5A = 90 gal

End of Lesson 2


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MD0173 3-1

LESSON ASSIGNMENT

LESSON 3 Pesticide Safety.

LESSON ASSIGNMENT 3-1--3-17.


3-1. Identify the general precautions for safehandling and storage of pesticides.

3-2. Select the proper protective clothing andequipment to use when handling pesticides.

3-3. Identify criteria for proper pesticide mixing and

storage facilities.

3-4. Identify the environmental hazards andrestrictions on the use of pesticides.



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MD0173 3-2

Section I. PERSONNEL AND TRAINING

3-1. GENERAL

a. Department of Defense standards for insect and rodent control require thatmost pesticide dispersal and other insect and rodent control operations beaccomplished by trained and certified personnel. The basis for this requirement isoverwhelming. Within the past few years, hundreds of new pesticides have beendeveloped and still newer pesticides are being tested. These new chemicals permitnew approaches to pest control through their residual and other actions. To obtainmaximum effectiveness from these newer pesticides, it is necessary to know the biologyof the pests encountered so pesticides can be applied at the right time and at the rightplace. These newer pesticides present a wide range of hazard in their use. If correctlyused, they may be quite safe. If they are mishandled, they may present a considerabledanger to the user, to the recipient of pest control service, or to the material being

treated.

b. Specialized equipment has been and is being developed to disperse thesenewer materials in a more effective and economical manner. New control techniqueshave been and are being devised. Because of these complexities, only persons withcapabilities for and a genuine interest in pest control should be assigned to pest controlprograms. Pest control personnel must be able to demonstrate their capabilities byqualifying for certification in order to comply with the certification requirements of theFederal Environmental Pesticide Control Act of 1972. Because of the rapidity ofdevelopments in chemicals, equipment, and techniques, they must be periodicallyreexamined and recertified.

3-2. PERSONNEL

a. Selection Criteria. Personnel should be carefully selected for pest controlpositions. Candidates must have the mental capacity to learn and an aptitude forbiological sciences and chemistry. Preferably, the candidate should be a high schoolgraduate with course work in biology and chemistry. It may be desirable to test thepotential of a candidate even before placing him in training status. Experience, by itself,should never be the criterion for employing pest control personnel. In addition to havingan adequate background and potential, the candidate must be genuinely interested inpest control work.

b. Training. Newly recruited personnel rarely will have the extensiveknowledge and experience necessary to properly perform their routine pest controlfunctions. These persons must be provided with on-the-job training. In addition, theyshould participate in correspondence-type instruction when it is sponsored periodicallyby the entomologists on the staffs of the major commands. The training courses shouldinclude responsibilities for insect and rodent control; insects and rodents as reservoirsand vectors of disease and as destroyers of property; identification, life history, habits;


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MD0173 3-3

and control of important pests; pesticides resistance; uses and characteristics ofinsecticides, rodenticides, fumigants, fungicides, herbicides, and equipment;administrative procedures; and safety precautions in handling, mixing, storing,transporting, and applying pesticides. Once the recruit has obtained a workingknowledge in the field of pest control, he should complete his training by attending the

Army, Navy, and Air Force Pest Management Certification Courses.

c. Recertification. The field of pest control is ever changing, withdevelopment of new materials, new equipment, and new research results ready to betranslated into operational usage. These developments make it necessary for pestcontrol personnel to receive periodic training. Recertification must be accomplishedevery 3 years and should consist of the following.

(1) A series of classes conducted by command pest managementprofessionals and augmented by instructors at a pest management training centerdesigned to refresh the knowledge of pest control personnel.

(2) A centrally held workshop or training conference at which installation oractivity pest control personnel are brought up-to-date with recent developments and areinstructed on the application of new developments to their programs.

(3) On-the-job instruction at their installation or activity.

d. Certification. All pest control personnel must be certified. It is throughcertification that commanding officers can be assured that personnel are qualified toconduct pest control operations in a safe, effective, and economical manner. To obtaincertification, a candidate must demonstrate to the satisfaction of the commandentomologist that he is qualified. Qualifications may be shown by passing a writtenexamination and by demonstrating on-the-job competency. As recertification is requiredevery 3 years, the centralized workshop or training conference offers a convenient timeand location for the certification examination. Observation of on-the-job competencemust be held at the activity or installation. Certificates can be withdrawn forincompetence, for negligence in safety precautions, for failure on written examination, orupon transfer to other duties.

Section II. SAFE HANDLING AND STORAGE

3-3. TOXICITY AND HAZARD

It is most important to distinguish between toxicity and hazard. Toxicity is thepotential of any chemical to produce damage. Toxicity was discussed in paragraph 1-4.Hazard is the probability that any given chemical will cause damage when used in aparticular way or place and, therefore, will vary greatly with local conditions andapplication methods. Frequently, a highly toxic chemical is less hazardous for a certain


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MD0173 3-4

use than one of a much lower basic toxicity. For example, parathion, a nonstandardorganophosphate which is extremely toxic (LD50 13 mg/kg or less), often present lesshazard than DDT from the standpoint of residues in food crops. Dieldrin is extremelyhazardous when the skin is contaminated with dusts or sprays, although its oral toxicityis similar to that of lindane, which is used next to the skin as a delousing powder. The

most toxic pesticide in a secured storeroom is less hazardous than the least toxicpesticide on a kitchen shelf. The type of formulation used also may have aconsiderable effect on the degree of hazard for the same chemical applied at the s

Documents

US Army Medical Course MD0173-100 - Pesticides in the Military